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Opinion Statement: Laser interstitial thermal therapy (LITT) is a minimally invasive treatment option for brain tumors including glioblastoma, other primary central nervous system (CNS) neoplasms, metastases, and radiation necrosis. LITT employs a fiber optic coupled laser delivery probe stabilized via stereotaxis to deliver thermal energy that induces coagulative necrosis in tumors to achieve effective cytoreduction. LITT complements surgical resection, radiation treatment, tumor treating fields, and systemic therapy, especially in patients who are high risk for surgical resection due to tumor location in eloquent regions or poor functional status. These factors must be balanced with the increased rate of cerebral edema post LITT compared to surgical resection. LITT has also been shown to induce transient disruption of the blood-brain barrier (BBB), especially in the peritumoral region, which allows for enhanced CNS delivery of anti-neoplastic agents, thus greatly expanding the armamentarium against brain tumors to include highly effective anti-neoplastic agents that have poor BBB penetration. In addition, hyperthermia-induced immunogenic cell death is another secondary side effect of LITT that opens up immunotherapy as an attractive adjuvant treatment for brain tumors. Numerous large studies have demonstrated the safety and efficacy of LITT against various CNS tumors and as the literature continues to grow on this novel technique so will its indications. [ABSTRACT FROM AUTHOR]

Surgical treatment of deep or difficult to access lesions represents a unique and significant challenge for pediatric neurosurgeons. The introduction of stereotactic magnetic resonance-guided laser interstitial thermal therapy (LITT) over the last decade has had a dramatic impact on the landscape of pediatric neurosurgery. LITT provides a safe and effective option for children with epilepsy from hypothalamic hamartoma that represents a ground-breaking new therapy for a condition which was historically very difficult to treat with previous neurosurgical techniques. LITT has also been used as an alternative surgical technique for mesial temporal sclerosis, focal cortical dysplasia, MR-negative epilepsy, cavernoma-related epilepsy, insular epilepsy, and corpus callosotomy among other epilepsy etiologies. In some cases, LITT has been associated with improved cognitive outcomes compared to standard techniques, as in mesial temporal lobe epilepsy. Initial experiences with LITT for neuro-oncologic processes are also promising. LITT is often attractive to patients and providers as a minimally invasive approach, but the differences in safety and clinical outcome between LITT and traditional approaches are still being studied. In this review, we examine the emerging indications and clinical evidence for LITT in pediatric neurosurgery.

More than 130-year ago, Sir Victor Horsley delivered a landmark address to the British Medical Association, in which he described successful localization and resection of an epileptogenic focus resulting in seizure freedom for the patient. Several important steps in epilepsy surgery have been achieved since, including resection techniques such as anterior temporal lobectomy and selective amygdalohippocampectomy, both resulting in 70–80% seizure freedom and distinct differences in neuropsychological outcomes. The most recent addition to techniques for epilepsy surgery is minimally invasive thermal therapy. Significant advances in imaging technology and thermal ablation have opened a novel avenue for epilepsy treatment, permitting surgical intervention with seizure-freedom rates approaching the success of traditional methods but with reduced invasiveness, blood loss and duration of postoperative hospital stay. Here, we review recent advances on stereotactic ablation techniques focused on epilepsy surgery. Finally, we present emerging navigation techniques, which allow a higher degree of freedom. The described technologies render precise navigation of the ablation probe to avoid critical structures along the trajectory path and open novel pathways to further minimize invasiveness and improve safety and efficacy. Improve safety and efficacy.

The blood-brain and blood-tumor barriers represent highly specialized structures responsible for tight regulation of molecular transit into the central nervous system. Under normal circumstances, the relative impermeability of the blood-brain barrier (BBB) protects the brain from circulating toxins and contributes to a brain microenvironment necessary for optimal neuronal function. However, in the context of tumors and other diseases of central nervous system, the BBB and the more recently appreciated blood-tumor barrier (BTB) represent barriers that prevent effective drug delivery. Overcoming both barriers to optimize treatment of central nervous system diseases remains the subject of intense scientific investigation. Although many newer technologies have been developed to overcome these barriers, thermal therapy, which dates back to the 1890 s, has been known to disrupt the BBB since at least the early 1980s. Recently, as a result of several technological advances, laser interstitial thermal therapy (LITT), a method of delivering targeted thermal therapy, has gained widespread use as a surgical technique to ablate brain tumors. In addition, accumulating evidence indicates that laser ablation may also increase local BBB/BTB permeability after treatment. We herein review the structure and function of the BBB and BTB and the impact of thermal injury, including LITT, on barrier function.

Purpose The aim of this paper is to discuss the current evidence for Laser Interstitial Thermal Therapy (LITT) in the treatment of brain metastases, our current recommendations for patient selection and the future perspectives for this therapy. We have also touched upon the possible complications and role of systemic therapy coupled with LITT for the treatment of brain metastases Material and Methods Two authors carried out the literature search using two databases independently, including PubMed, and Web of Science. The review included prospective and retrospective studies using LITT to treat brain metastases. Results Twenty-two original articles were analyzed in this review, particularly clinical outcomes and complications. We have also provided our institutional experience in the use of LITT to treat brain metastases and addressed future perspectives for the use of this technology. Conclusions The current literature supports LITT as a safe and effective therapy for patients with brain metastases that have failed SRS. Larger studies are still required to better evaluate the use of systemic therapy in concomitance with LITT. New images modalities may enable optimized treatment and outcomes.

Hyperthermia therapy (HT) of cancer is a well-known treatment approach. With the advent of new technologies, HT approaches are now important for the treatment of brain tumors. We review current clinical applications of HT in neuro-oncology and ongoing preclinical research aiming to advance HT approaches to clinical practice. Laser interstitial thermal therapy (LITT) is currently the most widely utilized thermal ablation approach in clinical practice mainly for the treatment of recurrent or deep-seated tumors in the brain. Magnetic hyperthermia therapy (MHT), which relies on the use of magnetic nanoparticles (MNPs) and alternating magnetic fields (AMFs), is a new quite promising HT treatment approach for brain tumors. Initial MHT clinical studies in combination with fractionated radiation therapy (RT) in patients have been completed in Europe with encouraging results. Another combination treatment with HT that warrants further investigation is immunotherapy. HT approaches for brain tumors will continue to a play an important role in neuro-oncology.

Epilepsy surgery is the most effective therapeutic approach for children with drug resistant epilepsy (DRE). Recent advances in neurosurgery, such as the Laser Interstitial Thermal Therapy (LITT), improved the safety and non-invasiveness of this method. Electric and magnetic source imaging (ESI/MSI) plays critical role in the delineation of the epileptogenic focus during the presurgical evaluation of children with DRE. Yet, they are currently underutilized even in tertiary epilepsy centers. Here, we present a case of an adolescent who suffered from DRE for 16 years and underwent surgery at Cook Children's Medical Center (CCMC). The patient was previously evaluated in a level 4 epilepsy center and treated with multiple antiseizure medications for several years. Presurgical evaluation at CCMC included long-term video electroencephalography (EEG), magnetoencephalography (MEG) with simultaneous conventional EEG (19 channels) and high-density EEG (256 channels) in two consecutive sessions, MRI, and fluorodeoxyglucose - positron emission tomography (FDG-PET). Video long-term EEG captured nine focal-onset clinical seizures with a maximal evolution over the right frontal/frontal midline areas. MRI was initially interpreted as non-lesional. FDG-PET revealed a small region of hypometabolism at the anterior right superior temporal gyrus. ESI and MSI performed with dipole clustering showed a tight cluster of dipoles in the right anterior insula. The patient underwent intracranial EEG which indicated the right anterior insular as seizure onset zone. Eventually LITT rendered the patient seizure free (Engel 1; 12 months after surgery). Retrospective analysis of ESI and MSI clustered dipoles found a mean distance of dipoles from the ablated volume ranging from 10 to 25 mm. Our findings highlight the importance of recent technological advances in the presurgical evaluation and surgical treatment of children with DRE, and the underutilization of epilepsy surgery in children with DRE.

Surgical management of drug-resistant epilepsy (DRE) in patients with multiple periventricular nodular heterotopias (PVNHs) is challenging. Identifying the location of seizure onset within these complex epileptic networks is difficult, and open resection carries risks of injury to surrounding functional white matter tracts such as optic radiations (ORs). The authors demonstrate tractography-assisted laser ablation of a single nodule in a patient with DRE and multiple PVNHs. Following surgery, visual fields were intact, highlighting the benefits of OR tractographic reconstruction. At 12 months postoperatively, the patient remained seizure free, suggesting the potential efficacy of targeting a single heterotopia within complex networks in well-selected cases. The video can be found here: https://stream.cadmore.media/r10.3171/2024.4.FOCVID2417., Competing Interests: Disclosures Dr. Weil reported personal fees from Monteris Medical outside the submitted work, and advisory board member for Synergia SA.Dr. Weil reported personal fees from Monteris Medical outside the submitted work, and advisory board member for Synergia SA., (© 2024, The Authors.)

Background: Laser interstitial thermal therapy (LITT) of intracranial tumors or radiation necrosis enables tissue diagnosis, cytoreduction, and rapid return to systemic therapies. Ablated tissue remains in situ, resulting in characteristic post-LITT edema associated with transient clinical worsening and complicating post-LITT response assessment., Methods: All patients receiving LITT at a single center for tumors or radiation necrosis from 2015 to 2023 with ≥9 months of MRI follow-up were included. An nnU-Net segmentation model was trained to automatically segment contrast-enhancing lesion volume (CeLV) of LITT-treated lesions on T1-weighted images. Response assessment was performed using volumetric measurements., Results: Three hundred and eighty four unique MRI exams of 61 LITT-treated lesions and 6 control cases of medically managed radiation necrosis were analyzed. Automated segmentation was accurate in 367/384 (95.6%) images. CeLV increased to a median of 68.3% (IQR 35.1-109.2%) from baseline at 1-3 months from LITT (P = 0.0012) and returned to baseline thereafter. Overall survival (OS) for LITT-treated patients was 39.1 (9.2-93.4) months. Lesion expansion above 40% from volumetric nadir or baseline was considered volumetric progression. Twenty-one of 56 (37.5%) patients experienced progression for a volumetric progression-free survival of 21.4 (6.0-93.4) months. Patients with volumetric progression had worse OS (17.3 vs 62.1 months, P = 0.0015)., Conclusions: Post-LITT CeLV expansion is quantifiable and resolves within 6 months of LITT. Development of response assessment criteria for LITT-treated lesions is feasible and should be considered for clinical trials. Automated lesion segmentation could speed the adoption of volumetric response criteria in clinical practice., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Purpose: The safety and effectiveness of laser interstitial thermal therapy (LITT) relies critically on the ability to continuously monitor the ablation based on real-time temperature mapping using magnetic resonance thermometry (MRT). This technique uses gradient recalled echo (GRE) sequences that are especially sensitive to susceptibility effects from air and blood. LITT for brain tumors is often preceded by a biopsy and is anecdotally associated with artifact during ablation. Thus, we reviewed our experience and describe the qualitative signal dropout that can interfere with ablation. Methods: We retrospectively reviewed all LITT cases performed in our intraoperative MRI suite for tumors between 2017 and 2020. We identified a total of 17 LITT cases. Cases were reviewed for age, sex, pathology, presence of artifact, operative technique, and presence of blood/air on post-operative scans. Results: We identified six cases that were preceded by biopsy, all six had artifact present during ablation, and all six were noted to have air/blood on their post-operative MRI or CT scans. In two of those cases, the artifactual signal dropout qualitatively interfered with thermal damage thresholds at the borders of the tumor. There was no artifact in the 11 non-biopsy cases and no obvious blood or air was noted on the post-ablation scans. Conclusion: Additional consideration should be given to pre-LITT biopsies. The presence of air/blood caused an artifactual signal dropout effect in cases with biopsy that was severe enough to interfere with ablation in a significant number of those cases. Additional studies are needed to identify modifying strategies. [ABSTRACT FROM AUTHOR]

Objective: Laser interstitial thermal therapy (LITT) for mesial temporal lobe epilepsy (mTLE) is typically performed with one trajectory to target the medial temporal lobe (MTL). MTL structures such as piriform and entorhinal cortex are epileptogenic, but due to their relative geometry, they are difficult to target with one trajectory while simultaneously maintaining adequate ablation of the amygdala and hippocampus. We hypothesized that a two‐trajectory approach could improve ablation of all relevant MTL structures. First, we created large‐scale computer simulations to compare idealized one‐ vs two‐trajectory approaches. A two‐trajectory approach was then validated in an initial cohort of patients. Methods: We used magnetic resonance imaging (MRI) from the Human Connectome Project (HCP) to create subject‐specific target structures consisting of hippocampus, amygdala, and piriform/entorhinal/perirhinal cortex. An algorithm searched for safe potential trajectories along the hippocampal axis (catheter one) and along the amygdala‐piriform axis (catheter two) and compared this to a single trajectory optimized over all structures. The proportion of each structure ablated at various burn radii was evaluated. A cohort of 11 consecutive patients with mTLE received two‐trajectory LITT; demographic, operative, and outcome data were collected. Results: The two‐trajectory approach was superior to the one‐trajectory approach at nearly all burn radii for all hippocampal subfields and amygdala nuclei (p <.05). Two‐laser trajectories achieved full ablation of MTL cortical structures at physiologically realistic burn radii, whereas one‐laser trajectories could not. Five patients with at least 1 year of follow‐up (mean = 21.8 months) experienced Engel class I outcomes; 6 patients with less than 1 year of follow‐up (mean = 6.6 months) are on track for Engel class I outcomes. Significance: Our anatomic analyses and initial clinical results suggest that LITT amygdalohippocampotomy performed via two‐laser trajectories may promote excellent seizure outcomes. Future studies are required to validate the long‐term clinical efficacy and safety of this approach. [ABSTRACT FROM AUTHOR]

PurposeThe safety and effectiveness of laser interstitial thermal therapy (LITT) relies critically on the ability to continuously monitor the ablation based on real-time temperature mapping using magnetic resonance thermometry (MRT). This technique uses gradient recalled echo (GRE) sequences that are especially sensitive to susceptibility effects from air and blood. LITT for brain tumors is often preceded by a biopsy and is anecdotally associated with artifact during ablation. Thus, we reviewed our experience and describe the qualitative signal dropout that can interfere with ablation.MethodsWe retrospectively reviewed all LITT cases performed in our intraoperative MRI suite for tumors between 2017 and 2020. We identified a total of 17 LITT cases. Cases were reviewed for age, sex, pathology, presence of artifact, operative technique, and presence of blood/air on post-operative scans.ResultsWe identified six cases that were preceded by biopsy, all six had artifact present during ablation, and all six were noted to have air/blood on their post-operative MRI or CT scans. In two of those cases, the artifactual signal dropout qualitatively interfered with thermal damage thresholds at the borders of the tumor. There was no artifact in the 11 non-biopsy cases and no obvious blood or air was noted on the post-ablation scans.ConclusionAdditional consideration should be given to pre-LITT biopsies. The presence of air/blood caused an artifactual signal dropout effect in cases with biopsy that was severe enough to interfere with ablation in a significant number of those cases. Additional studies are needed to identify modifying strategies.

Background: Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive treatment modality for ablation of low-grade glioma (LGG) and radiation necrosis (RN). Objective: To evaluate the efficacy, safety, and survival outcomes of patients with radiographically presumed recurrent or newly diagnosed LGG and RN treated with LITT. Methods: The neuro-oncological database of a quaternary center was reviewed for all patients who underwent LITT for management of LGG between 1 January 2013 and 31 December 2020. Clinical data including demographics, lesion characteristics, and clinical and radiographic outcomes were collected. Kaplan–Meier analyses comprised overall survival (OS) and progression-free survival (PFS). Results: Nine patients (7 men, 2 women; mean [SD] age 50 [16] years) were included. Patients underwent LITT at a mean (SD) of 11.6 (8.5) years after diagnosis. Two (22%) patients had new lesions on radiographic imaging without prior treatment. In the other 7 patients, all (78%) had surgical resection, 6 (67%) had intensity-modulated radiation therapy and chemotherapy, respectively, and 4 (44%) had stereotactic radiosurgery. Two (22%) patients had lesions that were wild-type IDH1 status. Volumetric assessment of preoperative T1-weighted contrast-enhancing and T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences yielded mean (SD) lesion volumes of 4.1 (6.5) cm3 and 26.7 (27.9) cm3, respectively. Three (33%) patients had evidence of radiographic progression after LITT. The pooled median (IQR) PFS for the cohort was 52 (56) months, median (IQR) OS after diagnosis was 183 (72) months, and median (IQR) OS after LITT was 52 (60) months. At the time of the study, 2 (22%) patients were deceased. Conclusions: LITT is a safe and effective treatment option for management of LGG and RN, however, there may be increased risk of permanent complications with treatment of deep-seated subcortical lesions.

• LITT is difficult after craniectomy due to lack of bony surface to anchor the bolt. • A 3D-printed implant was used to enable LITT targeting of a posterior fossa lesion. • The customized plate had a built-in bolt trajectory that aligned with the tumor. • The customized plate was implemented under the FDA expanded access pathway. • This strategy enables use of LITT in patients who would not otherwise be candidates. Laser interstitial thermal therapy (LITT) is a minimally invasive neurosurgical technique that has been demonstrated to successfully ablate intracranial tumors. While LITT for supratentorial lesions can often be straightforward, ablation of infratentorial lesions can be difficult with current targeting technologies and instrumentation. The anatomical difficulty of targeting posterior fossa masses can be further complicated in patients who have had a prior craniectomy or other procedure that removed the bone that is required to set the surgical trajectory. This article describes use of a three-dimensional (3D)–printed customized surgical implant to improve and enable targeting of posterior fossa lesions using LITT, particularly in the setting of prior craniectomy. A 3D-printed implant was customized for a patient with a history of metastatic lung cancer and prior posterior fossa craniectomy who presented for treatment of a progressively enlarging contrast-enhancing lesion in the right cerebellar hemisphere. The device included a built-in bolt trajectory for LITT ablation. The temporary implant was successfully fabricated for use with laser ablation of a right cerebellar mass. Three potential trajectories for the LITT bolt were incorporated into the temporary implant, but only the primary trajectory was utilized. Laser ablation was performed with the implant and a SideFire laser probe. Customized 3D-printed implants can enable the use of LITT for patients who would not otherwise be candidates. [ABSTRACT FROM AUTHOR]

We describe our single-institutional experience with magnetic resonance−guided stereotactic laser ablation (SLA) for the treatment of newly diagnosed and recurrent pediatric brain tumors. Eighteen consecutive ablation procedures were performed in 17 patients from March 2016−April 2020. Patient demographics, indications, procedures, neuroimaging features, and outcomes were reviewed retrospectively. Seventeen patients (mean age of 11.4 years, 11 boys, 6 girls) underwent SLA with a mean follow-up of 24 months (range: 3–45 months). Tumor histologies included pilocytic astrocytoma (n = 5), ganglioglioma (n = 3), low-grade glioma not otherwise specified (n = 4), glioblastoma (n = 2), meningioma (n = 1), medulloblastoma (n = 1), and metastatic malignant peripheral nerve sheath tumor (n = 1). SLA was first-line therapy in 10 patients. Mean procedure duration including anesthesia time was 328 minutes (range: 244–529 minutes), and mean postoperative length of stay was 1.5 days (range 1–5 days). The complication rate was 29%, which included 3 patients who experienced postoperative motor changes, which resolved within several weeks of surgery, 1 patient with self-limited intraoperative bradycardia and hypotension, and 1 patient who died postoperatively due to intracranial hemorrhage from a distant lesion. Twelve of 17 patients had a neuroimaging response after SLA (4 complete responses, 8 partial responses, 1 stable disease). Percentage of tumor shrinkage from baseline ranged from 33%−100% (mean 75%). Patients with low-grade glioma exhibited the best responses to SLA (range 3%−100% decrease; mean 90%; 36% complete response rate). SLA is a minimally invasive modality for the treatment of newly diagnosed and recurrent low-grade pediatric brain tumors. Low-grade glioma exhibited the best responses. Identification of ideal candidates for SLA, mitigation of perioperative complications, and demonstration of long-term outcomes need to be better defined in a clinical trial setting. [ABSTRACT FROM AUTHOR]

Negative MRI and an epileptogenic zone (EZ) adjacent to eloquent areas are two main issues that can be encountered during pre-surgical evaluation for epilepsy surgery. Focal Cortical Dysplasia type II (FCD type II) is the most common aetiology underlying a negative MRI. The objective of this study is to present three cases of pediatric patients exhibiting negative MRI and a seizure onset zone close to eloquent areas, who previously underwent traditional open surgery or SEEG-guided radiofrequency thermocoagulations (RF-TC). After seizure seizure recrudescence, pre-surgical SEEG was re-evaluated and Magnetic Resonance-guided laser interstitial thermal therapy (MRg-LiTT) was performed. We discuss the SEEG patterns, the planning of laser probes trajectories and the outcomes one year after the procedure. Pediatric patients who underwent SEEG followed by MRg-LiTT for drug-resistant epilepsy associated with FCD type II at our Centre were included. Pre-surgical videoEEG (vEEG), stereoEEG (sEEG), and MRI were reviewed. Post-procedure clinical outcome (measured by Engel score) and complications rates were evaluated. Three patients underwent 3 MRg-LiTT procedures from January 2022 to June 2022. Epileptogenic zone was previously studied via SEEG in all the patients. All the three patients pre-surgical MRI was deemed negative. Mean age at seizure onset was 47 months (21–96 months), mean age at MRg-LiTT was 12 years (10 years 10 months – 12 years 9 months). Engel class Ia outcome was achieved in patients #2 and #3, Engel class Ib in patient #1. Mean follow-up length was of 17 months (13 months – 20 months). Complications occurred in one patient (patient #2, extradural hematoma). The combined use of SEEG and MRg-LiTT in complex cases can lead to good outcomes both as a rescue therapy after failed surgery, but also as an alternative to open surgery after a successful SEEG-guided Radiofrequency Thermocoagulation (RF-TC). Specific SEEG patterns and a previous good outcome from RF-TC can be predictors of a favourable outcome. [ABSTRACT FROM AUTHOR]

Abstract MRI-guided laser interstitial thermal therapy (LITT) is the selective ablation of a lesion or a tissue using heat emitted from a laser device. LITT is considered a less invasive technique compared to open surgery that provides a nonsurgical solution for patients who cannot tolerate surgery. Although laser ablation has been used to treat brain lesions for decades, recent advances in MRI have improved lesion targeting and enabled real-time accurate monitoring of the thermal ablation process. These advances have led to a plethora of research involving the technique, safety, and potential applications of LITT. LITT is a minimally invasive treatment modality that shows promising results and is associated with decreased morbidity. It has various applications, such as treatment of glioma, brain metastases, radiation necrosis, and epilepsy. It can provide a safer alternative treatment option for patients in whom the lesion is not accessible by surgery, who are not surgical candidates, or in whom other standard treatment options have failed. Our aim is to review the current literature on LITT and provide a descriptive review of the technique, imaging findings, and clinical applications for neurosurgery.

Background: Ablative therapies have been used for the treatment of neurological disorders for many years. They have been used both for creating therapeutic lesions within dysfunctional brain circuits and to destroy intracranial tumors and space-occupying masses. Despite the introduction of new effective drugs and neuromodulative techniques, which became more popular and subsequently caused brain ablation techniques to fall out favor, recent technological advances have led to the resurgence of lesioning with an improved safety profile. Currently, the four main ablative techniques that are used for ablative brain surgery are radiofrequency thermoablation, stereotactic radiosurgery, laser interstitial thermal therapy and magnetic resonance-guided focused ultrasound thermal ablation. Object: To review the physical principles underlying brain ablative therapies and to describe their use for neurological disorders. Methods: The literature regarding the neurosurgical applications of brain ablative therapies has been reviewed. Results: Ablative treatments have been used for several neurological disorders, including movement disorders, psychiatric disorders, chronic pain, drug-resistant epilepsy and brain tumors. Conclusions: There are several ongoing efforts to use novel ablative therapies directed towards the brain. The recent development of techniques that allow for precise targeting, accurate delivery of thermal doses and real-time visualization of induced tissue damage during the procedure have resulted in novel techniques for cerebral ablation such as magnetic resonance-guided focused ultrasound or laser interstitial thermal therapy. However, older techniques such as radiofrequency thermal ablation or stereotactic radiosurgery still have a pivotal role in the management of a variety of neurological disorders.

Background: Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Management includes surgical resection followed by chemoradiation, and prognosis remains poor. Surgical resection is not possible for some deep-seated or eloquent tumors. Laser interstitial thermal therapy (LITT) has emerged as a new, minimally invasive surgical option for deep-seated GBM. Case Description: We report a case of newly diagnosed thalamic GBM managed with LITT followed by radiation and chemotherapy. Conclusion: The patient remains well at 50-month post-LITT, indicating a potentially unique durability of LITT treatment in GBM. [ABSTRACT FROM AUTHOR]

Surgical resection has been shown to prolong survival in patients with glioblastoma multiforme (GBM), although this benefit has not been demonstrated for reoperation following tumor recurrence. Laser interstitial thermal therapy (LITT) is a minimally invasive ablation technique that has been shown to effectively reduce tumor burden in some patients with intracranial malignancy. The aim of this study was to describe the safety and efficacy of LITT for recurrent and newly diagnosed GBM at a large tertiary referral center. Patients with GBM receiving LITT were retrospectively analyzed. Overall survival from the time of LITT was the primary end point measured. There were 69 patients identified for inclusion in this study. The median age of the cohort was 56 years (range, 15–77 years). Median tumor volume was 10.4 cm3 (range, 1.0–64.0 cm3). A Kaplan-Meier estimate of median overall survival for the series from the time of LITT was 12 months (95% confidence interval 8–16 months). Median progression-free survival for the cohort from LITT was 4 months (95% confidence interval 3–7 months). Adjuvant chemotherapy significantly prolonged progression-free survival and overall survival (P < 0.01 for both) in the cohort. Gross total ablation was not significantly associated with progression-free survival (P = 0.09). LITT can safely reduce intracranial tumor burden in patients with GBM who have exhausted other adjuvant therapies or are poor candidates for conventional resection techniques. [ABSTRACT FROM AUTHOR]

Laser interstitial thermal therapy (LITT) has become a popular tool in the treatment of tumors and epilepsy. While most commonly used for the treatment of mesial temporal lobe epilepsy, it can be used as a minimally invasive option for the treatment of any seizure focus but has very rarely been discussed in the setting of cortical dysplasia. Here, we discuss the case of a 5-year-old girl with medically refractory epilepsy secondary to a right medial orbital gyrus and gyrus rectus cortical dysplasia successfully treated with LITT. After confirmation of seizure focus using stereo electroencephalography (SEEG), the patient underwent thermal ablation of the focus through an eyebrow incision with use of a single laser fiber. She has been seizure-free 6 months postoperatively, only on one anti-seizure medication, with normal EEG. The use of LITT in this case was successful because of the cylindrical shape of the cortical dysplasia, making it easily accessible via a single laser fiber in the absence of a yet to develop fontal sinus. While open resection would have also been appropriate, the use of LITT provided a minimally invasive alternative approach that allowed for an excellent outcome with limited risks. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is the most common primary brain tumor with a dismal prognosis. Current standard of treatment is safe maximal tumor resection followed by chemotherapy and radiation. Altered cerebral microcirculation and elevated blood‐tumor barrier (BTB) permeability in tumor periphery due to glioma‐induced vascular dysregulation allow T1 contrast‐enhanced visualization of resectable tumor boundaries. Newer tracers that label the tumor and its vasculature are being increasingly used for intraoperative delineation of glioma boundaries for even more precise resection. Fluorescent 5‐aminolevulinic acid (5‐ALA) and indocyanine green (ICG) are examples of such intraoperative tracers. Recently, magnetic resonance imaging (MRI)–based MR thermometry is being employed for laser interstitial thermal therapy (LITT) for glioma debulking. However, aggressive, fatal recurrence always occurs. Postsurgical chemotherapy is hampered by the inability of most drugs to cross the blood‐brain barrier (BBB). Understanding postsurgical changes in brain microcirculation and permeability is crucial to improve chemotherapy delivery. It is important to understand whether any microcirculatory indices can differentiate between true recurrence and radiation necrosis. LITT leads to peri‐ablation BBB opening that persists for several weeks. Whether it can be a conduit for chemotherapy delivery is yet to be explored. This review will address the role of cerebral microcirculation in such emerging ideas in GBM diagnosis and therapy. [ABSTRACT FROM AUTHOR]

BACKGROUND AND PURPOSE: Magnetic resonance‐guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive procedure that produces real‐time thermal damage estimates (TDEs) of ablation. Currently, MRgLITT software provides limited quantitative parameters for intraoperative monitoring, but orthogonal TDE‐MRI slices can be utilized to mathematically estimate ablation volume. The objective of this study was to model TDE volumes and validate using post‐24 hours MRI ablative volumes. METHODS: Ablations were performed with the Visualase Laser Ablation System (Medtronic). Using ellipsoidal parameters determined for dual‐TDEs from orthogonal MRI planes, TDE volumes were calculated by two definite integral methods (A and B) implemented in Matlab (MathWorks). Post‐24 hours MRI ablative volumes were measured in OsiriX (Pixmeo) by two‐blinded raters and compared to TDE volumes via paired t‐test and Pearson's correlations. RESULTS: Twenty‐two ablations for 20 patients with various intracranial pathologies were included. Average TDE volume calculated with method A was 3.44 ± 1.96 cm3 and with method B was 4.83 ± 1.53 cm3. Method A TDE volumes were significantly different than post‐24 hours volumes (P <.001). Method B TDE volumes were not significantly different than post‐24 hours volumes (P =.39) and strongly correlated with each other (r =.85, R2 =.72, P <.0001). A total of eight of 22 (36%) method A versus 17 of 22 (77%) method B TDE volumes were within 25% of the post‐24 hours ablative volume. CONCLUSION: We present a viable mathematical method integrating dual‐plane TDEs to calculate volumes. Future algorithmic iterations will incorporate additional calculated variables that improve ablative volume estimations. [ABSTRACT FROM AUTHOR]

Purpose of Review: This review summarizes the modern approach to surgical management of malignant brain tumors, highlighting new technology and multimodal treatment paradigms. Recent Findings: Outcomes in patients with glioblastoma are strongly correlated with extent of initial surgical resection. Intraoperative MRI, 5-ALA, and neuronavigation are surgical tools that can help achieve a maximal safe resection. Stereotactic radiosurgery and brachytherapy can be used to enhance local control for brain metastases in conjunction with surgery, while combinatorial approaches are increasingly employed in patients with multiple metastases. Advances in surgical techniques allow for minimally invasive approaches, including the use of tubular retractors, endoscopes, and laser interstitial thermal therapy. Summary: Primary and metastatic brain tumors require a multimodal, multidisciplinary approach to treatment. Surgical resection can be paired with radiation for metastases to maximize tumor control, expanding systemic options. Technological innovations have improved the safety of surgical resection, while expanding the surgical options and indications for treatment. [ABSTRACT FROM AUTHOR]

Introduction : Laser interstitial thermal therapy (LITT) remains a promising advance in the treatment of primary central nervous system malignancies. As indications for its use continue to expand, there has been growing interest in its ability to induce prolonged blood brain barrier (BBB) permeability through hyperthermia, potentially increasing the effectiveness of current therapeutics including BBB-impermeant agents and immunotherapy platforms. Methods: In this review, we highlight the mechanism of hyperthermic BBB disruption and LITT-induced immunogenic cell death in preclinical models and humans. Additionally, we summarize ongoing clinical trials evaluating a combination approach of LITT and immunotherapy, which will likely serve as the basis for future neuro-oncologic treatment paradigms. Results: There is evidence to suggest a highly immunogenic response to laser interstitial thermal therapy through activation of both the innate and adaptive immune response. These mechanisms have been shown to potentiate standard methods of oncologic care. There are only a limited number of clinical trials are ongoing to evaluate the utility of LITT in combination with immunotherapy. Conclusion: LITT continues to be studied as a possible technique to bridge the gap between exciting preclinical results and the limited successes seen in the field of neuro-oncology. Preliminary data suggests a substantial benefit for use of LITT as a combination therapy in several clinical trials. Further investigation is required to determine whether or not this treatment paradigm can translate into long-term durable results for primary intracranial malignancies. [ABSTRACT FROM AUTHOR]

Objective: Targeting accuracy presents a key factor in achieving maximal safe ablation in laser interstitial thermal therapy (LITT). The VarioGuide system has proven precise for brain biopsies, but data showing its accuracy in combination with LITT are limited. The aim of this study was to determine the phantom and in vivo accuracy of LITT probe placement using the VarioGuide system and to evaluate the effect of targeting error on maximum possible ablation volume., Methods: Stereotactic LITT probe placement was performed using the VarioGuide system in 3 phantom skulls. The same system was used in 10 patients treated with LITT, for which data were retrospectively analyzed. Target point error (TPE), target depth deviation (TDD), target lateral deviation (TLD), and angular deviation (AD) were derived from intraprocedural MRI scans of both the phantom and in vivo trajectories. In vivo, the effect of targeting error on the maximum reachable ablation was calculated as the difference between the planned maximal achievable tumor ablation (PTA) and the actual maximal achievable tumor ablation (ATA)., Results: In total, 24 phantom and 16 in vivo trajectories were analyzed. In the phantom setting, the median TPE was 3.3 mm and median AD was 1.9°. Targeting accuracy significantly decreased for longer trajectories and those less perpendicular to the skull. In patients, the authors observed a comparable median TPE of 4.0 mm but significantly higher AD of 3.2°. In vivo, targeting inaccuracy resulted in a median decrease in maximum achievable ablation volume of 6% as compared to the planned trajectory., Conclusions: The authors' study indicates that utilizing the VarioGuide system in combination with LITT yields an average targeting error as large as 4 mm, which was smaller for shorter and straighter trajectories. In patients, targeting inaccuracy resulted in a median 6% decrease of the planned tumor ablation volume. These are important factors that should be considered in optimal case planning and patient selection in LITT.

Objective: MRI-guided laser interstitial thermal therapy (MRgLITT) has recently gained interest as an ablative stereotactic procedure for intractable epilepsy, movement disorders, and brain tumors. Conventionally, a LITT system consists of a laser generator and cooled laser applicator, which is a fiber optic core surrounded by a sheath through which cooled fluid is pumped. However, this footprint can make the system bulky and nonmobile, limit the maximum depth of targeting, and increase the chances of breakdown. Herein, the authors conduct a preclinical assessment of a noncooled MRgLITT system in a porcine model., Methods: Three-tesla MRI was used to guide the in vivo placement of noncooled laser applicators in the porcine brain. The study consisted of a survival arm and terminal arm. The laser was activated at a power of 4-7 W for ≤ 180 seconds. Temperature changes were monitored using the MR thermometry software ThermoGuide in the survival arm (n = 5) or both ThermoGuide software and adjacently inserted thermal probes in the terminal arm (n = 3). Thermal damage was determined by the software using the temperature-time relationship of cumulative equivalent minutes at 43°C (CEM43). Temperatures calculated by the software were compared with those recorded by the temperature probes. The dimensions of thermal damage thresholds (TDTs; 2-9, 10-59, 60-239, ≥ 240 CEM43 isolines) given by MR thermometry were compared with the dimensions of irreversible damage on histopathological analysis., Results: There was a strong correlation between temperature recordings by ThermoGuide and those by thermal probes at both 4 mm (r = 0.96) and 8 mm (r = 0.80), with a mean absolute error of 0.76°C ± 2.13°C and 0.17°C ± 1.65°C at 4 and 8 mm, respectively. The area of 2-9 CEM43 was larger than the area of irreversible damage seen on histopathological analysis. The dimensions of the 10 and 60 CEM43 correlated well with dimensions of the lesion on histopathological analysis. A well-defined border (≤ 1 mm) was observed between the area of irreversible damage and healthy brain tissue., Conclusions: This preclinical assessment showed that the noncooled LITT system was able to precisely reach the target and create well-defined lesions within a margin of safety, without any adverse effects. MR thermometry software provided an accurate near-real-time temperature of the brain tissue, and dimensions of the lesion as visualized by the software correlated well with histopathological findings. Further studies to test the system's efficacy and safety in human subjects are in progress.

Objective: Meningiomas are the most common primary brain tumors in adults and a subset are aggressive lesions resistant to standard therapies. Laser interstitial thermal therapy (LITT) has been successfully applied to other brain tumors, and recent work aims to explore the safety and long-term outcome experiences of LITT for both new and recurrent meningiomas. The authors' objective was to report safety and outcomes data of the largest cohort of LITT-treated meningioma patients to date., Methods: Eight United States-based hospitals enrolled patients with meningioma in the Laser Ablation of Abnormal Neurological Tissue Using Robotic NeuroBlate System (LAANTERN) prospective multicenter registry and/or contributed additional retrospective enrollments for this cohort study. Demographic, procedural, safety, and outcomes data were collected and analyzed using standard statistical methods., Results: Twenty adult patients (12 prospective and 8 retrospective) with LITT-targeted meningiomas were accrued. Patients underwent LITT for new (6 patients) and recurrent (14 patients) tumors (ranging from the 1st to 12th recurrence). The 30-day complication rate was 10%. Twenty percent of patients (4/20) had exhausted all other treatment options. Median length of follow-up was 1.3 years. One-third of new (2/6) and one-half of recurrent (7/14) meningiomas had disease progression during follow-up. One-year estimated local control (LC), progression-free survival, and overall survival rates were 55.3%, 48.4%, and 86.3%, respectively. In the 12 patients who had ≥ 91% ablative coverage, 1-year estimated LC was 61.4%. The complication rate was 10% (2/20), with 1 complication being transient and resolving postoperatively., Conclusions: This cohort study supports the safety of the procedure for this tumor type. LITT can offer a much-needed treatment option, especially for patients with multiply recurrent meningiomas who have limited remaining alternatives.

To our knowledge, we report the first case of a cholangiocarcinoma brain metastasis successfully treated with magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy. In 2017, a 71-year-old man was diagnosed with unresectable intrahepatic cholangiocarcinoma. In August 2018, a brain MRI scan was performed after a transient episode of altered mental status and revealed a subcentimeter enhancing lesion in the deep white matter of the right cerebellum. Due to lack of symptoms and the small size of the lesion, it was initially observed. However, a follow-up MRI scan at 2.5 months demonstrated increased lesion size with worsening perilesional edema. Given the rarity of cholangiocarcinoma brain metastases and the deep location, the patient underwent stereotactic needle biopsy to confirm the diagnosis followed by laser ablation as a primary treatment for the metastasis. The patient tolerated the surgery well with no complications, and the postoperative course was uneventful. At 16 months postablation, there has been no recurrence or disease progression. Although prognosis for these tumors is poor, our result suggests that laser ablation can be an effective treatment for this rare entity and is a representative example of the expanding indications for laser interstitial thermal therapy. [ABSTRACT FROM AUTHOR]

Treatment strategies for glioblastoma multiforme (GBM) of the corpus callosum have remained limited to stereotactic biopsy in many cases owing to the morbidity resulting from aggressive surgical resection. We performed a study of 3 patients with histologically proven GBM of the corpus callosum who had undergone bilateral laser interstitial thermal therapy (LITT). The data collected included demographics, tumor location and volume, tumor genetic markers, treatment volume, perioperative complications, and Karnofsky performance scale (KPS) score pre- and postoperatively. We performed 6 LITT sessions for the 3 patients with GBM of the corpus callosum. The mean patient age was 64 years, with an average tumor volume of 14.95 cm3. The mean pretreatment KPS score was 80, and no significant changes were found in the KPS scores at 1 month postoperatively. The mean extent of ablation was 98.6% on postoperative magnetic resonance imaging, and none of the patients had experienced perioperative complications. At 8 months of follow-up, 2 of the 3 patients were alive and neurologically stable compared with their preoperative state. The third patient had elected to defer radiotherapy and oncology treatment and was lost to follow-up. The mean progression-free survival was 3.55 months, with interval satellite lesions seen on follow-up imaging studies. Although our case series was small, we have demonstrated for the first time, to the best of our knowledge, that bilateral LITT is a safe and effective treatment of GBM of the corpus callosum. Given the known benefit of near gross total resection for high-grade glioma, we believe LITT might improve survival for these patients who otherwise would have undergone biopsy. [ABSTRACT FROM AUTHOR]

Objective: Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive procedure that produces real-time thermal damage estimates (TDE) in orthogonal MRI-planes. The current system does not allow the user to quantify the TDE during the ablation process. We aim to characterize TDE dimensional expansion via a validated semi-automated algorithm. Methods: Selection criteria included single-laser catheter use, performed with the Visualase MRI-Guided Laser Ablation System. TDE lengths and widths relative to the laser path were calculated using a developed algorithm and validated with two raters’ manual measurements. MATLAB Blob Analysis was used to approximate TDE ellipsoidal major-minor axes. TDE length–width expansion was characterized by the power law f(x) = axk. Results: For analyses of 40 TDEs across 20 patients, minimal measurement differences, 0.2). No significant differences were observed between ratios of major-minor axes vs length–width (P = 0.19). For dynamic studies, 60 MRI planes across 30 patients were analyzed for linear regressions (R^2 = 0.70–0.99) from log-log plots of TDE dimensions vs time. Constant “a” for width (0.38 ± 0.17) was larger than length (0.28 ± 0.16) (P

We present neuropsychological and functional outcome data in a teenager undergoing stereotactic laser amygdalohippocampotomy (SLAH) who had drug-resistant mesial temporal lobe epilepsy due to left hippocampal sclerosis. Given strong baseline cognitive performance, there was concern for post-operative declines in language and verbal memory were this patient to undergo open resection. She was evaluated pre- and post-ablation with clinical and experimental neuropsychological measures including semantic memory, category-specific object/face recognition and naming, spatial learning, and socio-emotional processing. The patient became seizure-free following SLAH and experienced significant improvements in school performance and social engagement. She experienced improvement in recognition and naming of multiple object categories, memory functions, and verbal fluency. In contrast, the patient declined significantly in her ability to recognize emotional tone from facial expressions, a socio-emotional process that had been normal prior to surgery. We believe this decline was related to surgical disruption of the limbic system, an area highly involved in emotional processing, and suspect such deficits are an under-assessed and unrecognized risk for all surgeries involving the amygdalohippocampal complex and broader limbic system regions. We hope this positive SLAH outcome will serve as impetus for group level research to establish its safety and efficacy in the pediatric setting.

Background: Minimally invasive procedures are gaining widespread acceptance in difficult-to-access brain tumor treatment. Stereotactic radiosurgery (SRS) is the preferred choice, however, laser interstitial thermal therapy (LITT) has emerged as a tumor cytoreduction technique. The present meta-analysis compared current SRS therapy with LITT in brain tumors. Methods: A search was performed in Lilacs, PubMed, and Cochrane database. Patient's demographics, tumor location, therapy used, Karnofsky performance status score before treatment, and patient's outcome (median overall survival, progression-free survival, and adverse events) data were extracted from studies. The risk of bias was assessed by Cochrane collaboration tool. Results: Twenty-five studies were included in this meta-analysis. LITT and SRS MOS in brain metastasis patients were 12.8 months' versus 9.8 months (ranges 9.3-16.3 and 8.3-9.8; P = 0.02), respectively. In a combined comparison of adverse effects among LITT versus SRS in brain metastasis, we found 15% reduction in absolute risk difference (-0.16; 95% confidence interval P < 0.0001). Conclusion: We could not state that LITT treatment is an optimal alternative therapy for difficult-to-access brain tumors due to the lack of systematic data that were reported in our pooled studies. However, our results identified a positive effect in lowering the absolute risk of adverse events compared with SRS therapy. Therefore, randomized trials are encouraged to ascertain LITT role, as upfront or postoperative/post-SRS therapy for brain tumor treatment. [ABSTRACT FROM AUTHOR]

Stereotactic Radiosurgery has become the main treatment for patients with limited number of brain metastases (BM). Recently, with the increasing use of this modality, there is a growth in recurrence cases. Recurrence after radiation therapy can be divided in changes favoring either tumor recurrence or radiation necrosis (RN). Laser Interstitial Thermal Therapy (LITT) is minimally invasive treatment modality that has been used to treat primary and metastatic brain tumors. When associated with real-time thermometry using Magnetic Resonance Imaging, the extent of ablation can be controlled to provide maximum coverage and avoid eloquent areas. The objective of this study was to investigate the use of LITT in the treatment of BM. An extensive review of the relevant literature was conducted and the outcome results are discussed. There is an emphasis on safety and local control rate of patients treated with this modality. The findings of our study suggest that LITT is a viable safe technique to treat recurrent BM, especially in patients with deep-seated lesions where surgical resection is not an option. [ABSTRACT FROM AUTHOR]

Purpose: Magnetic resonance-guided laser interstitial thermal therapy (LITT) has been increasingly used to treat a number of intracranial pathologies, though its use in the posterior fossa has been limited to a few small series. We performed a multi-institutional review of targets in the posterior fossa, reporting the efficacy and safety profile associated with laser ablation in this region of the brain. Methods: A retrospective review of patients undergoing LITT in the posterior fossa was performed from August 2010 to March 2020. Patient demographic information was collected alongside the operative parameters and patient outcomes. Reported outcomes included local control of the lesion, postoperative complications, hospital length of stay, and steroid requirements. Results: 58 patients across four institutions underwent LITT in the posterior fossa for 60 tumors. The median pre-ablation tumor volume was 2.24 cm3. 48 patients (50 tumors) were available for follow-up. An 84% (42/50) overall local control rate was achieved at 9.5 months median follow up. There were two procedural complications, including insertional hemorrhage and laser misplacement and 12/58 (21%) patients developed new neurological deficits. There was one procedure related death. The median length of hospital stay was 1 day, with 20.7% of patients requiring discharge to a rehabilitation facility. Conclusions: LITT is an effective approach for treating pathology in the posterior fossa. The average target size is smaller than what has been reported in the supratentorial space. Care must be taken to prevent injury to surrounding structures given the close proximity of critical structures in this region. [ABSTRACT FROM AUTHOR]

Background: Laser interstitial thermal therapy (LITT) is a minimally invasive surgical treatment for multiple intracranial pathologies that are of growing interest to neurosurgeons and their patients and is emerging as an effective alternative to standard of care open surgery in the neurosurgical armamentarium. This option was initially considered for those patients with medical comorbidities and lesion-specific characteristics that confer excessively high risk for resection through a standard craniotomy approach but indications are changing. Methods: The PubMed database was searched for studies in the English literature on LITT for the treatment of primary and metastatic brain tumors, meningiomas, as well as for radiation necrosis (RN) in previously irradiated brain tumors. Results: This review provides an update of the relevant literature regarding application of LITT in neurosurgical oncology for the treatment of de novo and recurrent primary gliomas and brain metastases radiographically regrowing after previous irradiation as recurrent tumor or RN. In addition, this review details the limited experience of LITT with meningiomas and symptomatic peritumoral edema after radiosurgery. The advantages and disadvantages, indications, and comparisons to standard of care treatments such as craniotomy for open surgical resection are discussed for each pathology. Finally, the literature on cost-benefit analyses for LITT are reviewed. Conclusion: The studies discussed in this review have helped define the role of LITT in neurosurgical oncology and delineate optimal patient selection and tumor characteristics most suitable to this intervention. [ABSTRACT FROM AUTHOR]

Objective: Magnetic resonance imaging (MRI)–guided laser interstitial thermal therapy (MRg‐LITT) is an alternative to open epilepsy surgery. We assess safety and effectiveness of MRg‐LITT for extratemporal lobe epilepsy (ETLE) in patients who are considered less favorable for open resection. Methods: We retrospectively reviewed sequential cases of patients with focal ETLE who underwent MRg‐LITT between 2012 and 2019. Epileptogenic zones were determined from standard clinical and imaging data ± stereoelectroencephalography (SEEG). Standard stereotactic techniques, MRI thermometry, and a commercial laser thermal therapy system were used for ablations. Anatomic MRI was used to calculate ablation volumes. Clinical outcomes were determined longitudinally. Results: Thirty‐five patients with mean epilepsy duration of 21.3 ± 12.2 years underwent MRg‐LITT for focal ETLE at a mean age 36.4 ± 12.7 years. A mean 2.59 ± 1.45 trajectories per patient were used to obtain ablation volumes of 8.8 ± 7.5 cm3. Mean follow‐up was 27.3 ± 19.5 months. Of 32 patients with >12 months of follow‐up, 17 (53%) achieved good outcomes (Engel class I + II) of whom 14 (44%) were Engel class I. Subgroup analysis revealed better outcomes for patients with lesional ETLE than for those who were nonlesional, multifocal, or who had failed prior interventions (P =.02). Of 13 patients showing favorable seizure‐onset patterns (localized low voltage fast activity or rhythmic spiking on SEEG) prior to ablation, 9 (69%) achieved good outcomes, whereas only 3 of 11 (27%) who show other slower onset patterns achieved good outcomes. Minor adverse events included six patients with transient sensorimotor neurologic deficits and four patients with asymptomatic hemorrhages along the fiber tract. Major adverse events included one patient with a brain abscess that required stereotactic drainage and one patient with persistent hypothalamic obesity. Three deaths—two seizure‐associated and one suicide—were unrelated to surgical procedures. Significance: MRI‐guided laser interstitial thermal therapy (or MRg‐LITT) was well‐tolerated and yielded good outcomes in a heterogeneous group of ETLE patients. Lesional epilepsy and favorable seizure‐onset patterns on SEEG predicted higher likelihoods of success. [ABSTRACT FROM AUTHOR]

Background Glioblastoma multiforme (GBM) is an aggressive intracranial malignancy that confers a poor prognosis despite maximum surgical resection and chemoradiotherapy. Survival decreases further with deep-seated lesions. Laser interstitial thermal therapy (LITT) is an emerging minimally invasive technique for tumor ablation shown to reduce tumor burden effectively, particularly in deep-seated locations less amenable to gross total resection. We describe our initial technical experience of using the combination of LITT followed by surgical resection in patients with GBMs that exhibit both an easily accessible and deep-seated component. Materials and Methods Patients with GBM who received concurrent LITT and surgical resection at our institution were identified. Patient demographic and clinical information was procured from the University of Texas MD Anderson Cancer Center electronic medical record along with preoperative, postoperative, and 1-month follow-up magnetic resonance imaging (MRI). Results Four patients (n = 2 male, n = 2 female) with IDH -wild type GBM who received combined LITT and surgical resection were identified and analyzed retrospectively. All patients received chemoradiotherapy before presentation. All but one patient (75%) received resection before presentation. Median age was 54 years (range: 44–56 years). Median length of hospital stay was 6.5 days (range: 2–47 days). Median extent of combined ablation/resection was 90.4%. One of the four patients experienced complications in the perioperative or immediate follow-up periods. Local recurrence was observed in one patient during the follow-up period. Conclusion Malignant gliomas in deep-seated locations or in close proximity to white matter structures are challenging to manage. LITT followed by surgical resection may provide an alternative for tumor debulking that minimizes potential morbidities and extent of residual tumor. Further studies comparing this approach with standard resection techniques are warranted. [ABSTRACT FROM AUTHOR]

Thermal coagulation is a central principle in surgery, particularly regarding hemostasis, as well as being an integral part of intracranial tumor removal. Traditionally, surgical hemostasis is achieved through application of unipolar or bipolar electrocautery. This method has been contemporized and specialized to treat intracranial tumors through a technique called stereotactic laser ablation (SLA), also known as laser interstitial thermal therapy. In this article, we present this technique as an additional option in the treatment of difficult intracranial tumors. Specifically, we report here a highly vascular and hemorrhagic pineocytoma found in a fragile, elderly patient who underwent a novel combination of procedures: SLA mediated devascularization followed by resection via an endoscopic approach. SLA-mediated thermal-coagulation is a potential strategy for minimizing hemorrhagic risks in brain tumor resection and may be used in conjunction with other approaches tailored to the patient and their disease. [ABSTRACT FROM AUTHOR]

Brainstem cavernous malformations (CMs) often have high hemorrhage rates and significant posthemorrhage morbidity. The authors present two cases in which magnetic resonance thermography-guided laser interstitial therapy was used for treatment of pontine CMs after recurrent hemorrhage. Both patients showed significant symptomatic improvement and were hemorrhage-free at 12- and 6-month follow-up, respectively. Each had radiographic evidence of lesion involution on serial follow-up imaging. These early results demonstrate this treatment modality may be technically safe; however, larger case numbers and longer follow-up are needed to demonstrate efficacy. [ABSTRACT FROM AUTHOR]

The blood-brain and blood-tumor barriers represent highly specialized structures responsible for tight regulation of molecular transit into the central nervous system. Under normal circumstances, the relative impermeability of the blood-brain barrier (BBB) protects the brain from circulating toxins and contributes to a brain microenvironment necessary for optimal neuronal function. However, in the context of tumors and other diseases of central nervous system, the BBB and the more recently appreciated blood-tumor barrier (BTB) represent barriers that prevent effective drug delivery. Overcoming both barriers to optimize treatment of central nervous system diseases remains the subject of intense scientific investigation. Although many newer technologies have been developed to overcome these barriers, thermal therapy, which dates back to the 1890 s, has been known to disrupt the BBB since at least the early 1980s. Recently, as a result of several technological advances, laser interstitial thermal therapy (LITT), a method of delivering targeted thermal therapy, has gained widespread use as a surgical technique to ablate brain tumors. In addition, accumulating evidence indicates that laser ablation may also increase local BBB/BTB permeability after treatment. We herein review the structure and function of the BBB and BTB and the impact of thermal injury, including LITT, on barrier function. [ABSTRACT FROM AUTHOR]

The aim of this paper is to discuss the current evidence for Laser Interstitial Thermal Therapy (LITT) in the treatment of brain metastases, our current recommendations for patient selection and the future perspectives for this therapy. We have also touched upon the possible complications and role of systemic therapy coupled with LITT for the treatment of brain metastases Two authors carried out the literature search using two databases independently, including PubMed, and Web of Science. The review included prospective and retrospective studies using LITT to treat brain metastases. Twenty-two original articles were analyzed in this review, particularly clinical outcomes and complications. We have also provided our institutional experience in the use of LITT to treat brain metastases and addressed future perspectives for the use of this technology. The current literature supports LITT as a safe and effective therapy for patients with brain metastases that have failed SRS. Larger studies are still required to better evaluate the use of systemic therapy in concomitance with LITT. New images modalities may enable optimized treatment and outcomes. [ABSTRACT FROM AUTHOR]

Hyperthermia therapy (HT) of cancer is a well-known treatment approach. With the advent of new technologies, HT approaches are now important for the treatment of brain tumors. We review current clinical applications of HT in neuro-oncology and ongoing preclinical research aiming to advance HT approaches to clinical practice. Laser interstitial thermal therapy (LITT) is currently the most widely utilized thermal ablation approach in clinical practice mainly for the treatment of recurrent or deep-seated tumors in the brain. Magnetic hyperthermia therapy (MHT), which relies on the use of magnetic nanoparticles (MNPs) and alternating magnetic fields (AMFs), is a new quite promising HT treatment approach for brain tumors. Initial MHT clinical studies in combination with fractionated radiation therapy (RT) in patients have been completed in Europe with encouraging results. Another combination treatment with HT that warrants further investigation is immunotherapy. HT approaches for brain tumors will continue to a play an important role in neuro-oncology. [ABSTRACT FROM AUTHOR]

Surgical treatment of deep or difficult to access lesions represents a unique and significant challenge for pediatric neurosurgeons. The introduction of stereotactic magnetic resonance-guided laser interstitial thermal therapy (LITT) over the last decade has had a dramatic impact on the landscape of pediatric neurosurgery. LITT provides a safe and effective option for children with epilepsy from hypothalamic hamartoma that represents a ground-breaking new therapy for a condition which was historically very difficult to treat with previous neurosurgical techniques. LITT has also been used as an alternative surgical technique for mesial temporal sclerosis, focal cortical dysplasia, MR-negative epilepsy, cavernoma-related epilepsy, insular epilepsy, and corpus callosotomy among other epilepsy etiologies. In some cases, LITT has been associated with improved cognitive outcomes compared to standard techniques, as in mesial temporal lobe epilepsy. Initial experiences with LITT for neuro-oncologic processes are also promising. LITT is often attractive to patients and providers as a minimally invasive approach, but the differences in safety and clinical outcome between LITT and traditional approaches are still being studied. In this review, we examine the emerging indications and clinical evidence for LITT in pediatric neurosurgery. [ABSTRACT FROM AUTHOR]

Epilepsy with periventricular nodular heterotopia (PVNH) lacks a conclusive surgical treatment strategy as eloquent cortex and important white matter tracts frequently overlay the deep periventricular nodules. Our goal was to evaluate the safety and efficacy of laser interstitial thermal therapy (LITT) for the treatment of epilepsy in PVNH. Data on demographic characteristics, complications, visual outcomes, Engel classification at last follow-up, antiepileptic drug use, morbidity, and mortality among patients who underwent this procedure were retrospectively reviewed. Between May 2015 and January 2019, 5 patients underwent 6 LITT procedures for epilepsy with PVNH. One patient had residual nodules after their first procedure and underwent a second ablation. The average follow-up time was 12 months. Three patients were Engel class Ia, 1 patient was Engel class II, and 1 patient was Engel class III at last follow-up. Two patients were able to reduce their antiepileptic drugs postoperatively. Three patients had no changes in vision, 1 patient experienced a quadrantanopsia, and 1 patient had subjective blurry vision after their procedures. No patients experienced motor deficits, dysphasia, infection, or mortality. LITT appears to be a safe and promising option to provide seizure relief for patients with refractory epilepsy and PVNH that otherwise may not be surgical candidates. Some appropriately determined patients with refractory epilepsy may benefit from LITT before proceeding with an invasive intracranial evaluation. A larger sample size and long-term follow-up is necessary to further elucidate safety and efficacy. [ABSTRACT FROM AUTHOR]

Brain metastasis (BM) affects up to one-third of adults with cancer and carries a historically bleak prognosis. Despite advances in stereotactic radiosurgery (SRS), rates of in-field recurrence (IFR) after SRS range from 10 to 25%. High rates of neurologic death have been reported after SRS failure, particularly for recurrences deep in the brain and surgically inaccessible. Laser interstitial thermal therapy (LITT) is an emerging option in this setting, but its ability to prevent a neurologic death is unknown. In this study, we investigate the causes of death among patients with BM who undergo LITT for IFR after SRS. We conducted a single institution retrospective case series of patients with BM who underwent LITT for IFR after SRS. Clinical and demographic data were collected via chart review. The primary endpoint was cause of death. Between 2010 and 2018, 70 patients with BM underwent LITT for IFR after SRS. Median follow-up after LITT was 12.0 months. At analysis, 49 patients died; a cause was determined in 44. Death was neurologic in 20 patients and non-neurologic in 24. The 24-month cumulative incidence of neurologic and non-neurologic death was 35.1% and 38.6%, respectively. Etiologies of neurologic death included local recurrence (n = 7), recovery failure (n = 7), distant progression (n = 5), and other (n = 1). Among our patient population, LITT provided the ability to stabilize neurologic disease in up to 2/3 of patients. For IFR after SRS, LITT may represent a reasonable treatment strategy for select patients. Additional work is necessary to determine the extent to which LITT can prevent neurologic death after recurrence of BM. [ABSTRACT FROM AUTHOR]